StreamApiUtil: fix addition of map operation when object-object cast is involved

java/java-impl/src/com/intellij/refactoring/chainCall/ChainCallExtractor.java

@@ -19,6 +19,7 @@ import com.intellij.codeInspection.LambdaCanBeMethodReferenceInspection;
 import com.intellij.codeInspection.util.OptionalUtil;
 import com.intellij.openapi.extensions.ExtensionPointName;
 import com.intellij.openapi.project.Project;
+import com.intellij.openapi.util.text.StringUtil;
 import com.intellij.psi.*;
 import com.intellij.psi.codeStyle.CodeStyleManager;
 import com.intellij.psi.util.PsiTreeUtil;
@@ -104,7 +105,8 @@ public interface ChainCallExtractor {
     PsiMethodCallExpression call = tryCast(args.getParent(), PsiMethodCallExpression.class);
     if (call == null) return null;
     for(ChainCallExtractor extractor : KEY.getExtensions()) {
-      if(extractor.canExtractChainCall(call, expression, targetType)) {
+      if(extractor.canExtractChainCall(call, expression, targetType) &&
+         StringUtil.isNotEmpty(extractor.getMethodName(parameter, expression, targetType))) {
         return extractor;
       }
     }

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/streamApiMigration/afterCollectCast.java

@@ -0,0 +1,12 @@
+// "Replace with collect" "true"
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Collectors;
+
+public class Main {
+  List<String> getStrings(List<?> list) {
+      List<String> result = list.stream().filter(o -> o instanceof String).map(o -> (String) o).collect(Collectors.toList());
+      return result;
+  }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/streamApiMigration/beforeCollectCast.java

@@ -0,0 +1,18 @@
+// "Replace with collect" "true"
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class Main {
+  List<String> getStrings(List<?> list) {
+    List<String> result = new ArrayList<>();
+    for (Object o : li<caret>st) {
+      if (o instanceof String) {
+        String s = (String) o;
+        result.add(s);
+
+      }
+    }
+    return result;
+  }
+}

plugins/InspectionGadgets/src/com/siyeh/ig/psiutils/StreamApiUtil.java

@@ -114,11 +114,11 @@ public class StreamApiUtil {
   public static String getShortcutMappingMethod(PsiVariable variable, @Nullable PsiType outType, PsiElement mapper) {
     if (!(mapper instanceof PsiExpression)) return null;
     PsiExpression expression = PsiUtil.skipParenthesizedExprDown(((PsiExpression)mapper));
-    if (expression instanceof PsiTypeCastExpression && Objects.equals(expression.getType(), outType)) {
+    PsiType inType = variable.getType();
+    if (expression instanceof PsiTypeCastExpression && inType instanceof PsiPrimitiveType && Objects.equals(expression.getType(), outType)) {
       expression = ((PsiTypeCastExpression)expression).getOperand();
     }
     if (ExpressionUtils.isReferenceTo(expression, variable)) {
-      PsiType inType = variable.getType();
       if (!(outType instanceof PsiPrimitiveType)) {
         return inType instanceof PsiPrimitiveType ? "boxed" : "";
       }